Hidradenitis suppurativa (HS) is a common (though rarely diagnosed), chronic skin disease characterized by clusters of abscesses or subcutaneous boil-like "infections" (oftentimes free of actual bacteria) that most commonly affects apocrine sweat gland bearing areas, such as the underarms, under the breasts, inner thighs, groin and buttocks.
Hidradenitis suppurativa commonly occurs around hair follicles, where many oil and sweat glands are found, such as in the armpits, groin and anal area.
Recent regional and insurance database studies indicate that diagnoses of hidradenitis suppurativa (HS) are rare, with fewer than 200,000 affected patients in the United States. These findings are at odds with the generally accepted prevalence of approximately 1%. To estimate the number of patients diagnosed with HS, including patients enrolled in public health plans and the uninsured, we performed an investigation using National Center for Health Statistics databases of visits to health care providers.